i tried to apply NTP configuration on OS9907 switch to act as NTP server and to provide time and the configuration as the following:

ntp master 4
ntp interface 10.10.10.1 enable
ntp max-associations 20

and i found that:

when the client is Alcatel OS4500 switches it working fine and the client is synchronized with the server
but when the client is third parity like Cisco call manager or Cisco router , or even Microsoft windows it doesn't work